Cell counter

Abstract

Cell counters and methods of their use are disclosed herein. The cell counters include a sample mounting system that includes a base, which includes a mounted lower sample surface and a cover having a mounted upper sample surface; a bright-field light source incorporated in the cover; an objective lens mounted below the sample mounting system; optionally, a fluorescence excitation source in optical communication with the sample mounting system; and an imaging system in optical communication with the bright-field light source and the objective lens. The mounted sample surfaces are configured for repeated use, such that disposable sample cartridges are not needed.

We claim: 
     
       1. A device for measuring cells or particles in a suspension, comprising:
 (i) a bright-field light source; 
 (ii) an imaging system; and 
 (iii) a sample mounting system comprising upper and lower sample surfaces configured for direct receipt of a sample comprising a suspension of cells or particles, the system comprising:
 (A) a base having a base top side, a base bottom side, and an objective lens cavity located on the base so as to align with and receive one or more objective lenses of the imaging system; 
 (B) a hinge fixed to the base; 
 (C) a movable arm fixed to the hinge, said movable arm having a movable arm top side, a movable arm bottom side, and a bright-field light source cavity located on a portion of the movable atm distal to the hinge and configured to receive the bright-field light source; 
 (D) the lower sample surface mounted to the base top side in a position configured to receive bright-field light from the bright-field light source when the movable arm is in a closed position; and 
 (E) the upper sample surface mounted to the movable arm bottom side of the movable arm in a position configured to receive bright-field light from the bright field light source; 
 wherein a distance between the lower sample surface and the upper sample surface when the moveable arm is in the closed position is adjustable to accommodate variable volumes of samples deposited between the upper and lower sample surfaces; 
 wherein the system is re-usable by moving the movable arm to an open position and cleaning the sample surfaces. 
 
 
     
     
       2. The device of  claim 1 , wherein the imaging system comprises a plurality of objective lenses, wherein at least one objective lens is aligned with the objective lens cavity of the sample mounting system. 
     
     
       3. The device of  claim 2 , further comprising a plurality of fluorescent excitation sources. 
     
     
       4. The device of  claim 1 , further comprising at least one fluorescence excitation source; wherein the lower sample surface is configured to receive fluorescent light from the at least one fluorescence excitation source and/or the upper sample surface is configured to receive fluorescent light from the at least one fluorescence excitation source when the movable arm is in the closed position. 
     
     
       5. The device of  claim 1 , wherein the sample comprises a suspension of cells, selected from prokaryotic and eukaryotic cells. 
     
     
       6. The device of  claim 1 , wherein the sample mounting system comprises a calibrator for detecting and/or calibrating distance between the lower sample surface and the upper sample surface. 
     
     
       7. The device of  claim 6 , wherein the calibrator comprises a distance sensor disposed in one or both of the base and the movable arm. 
     
     
       8. The device of  claim 1 , wherein the sample mounting system comprises a height adjustment pin in one of the base or the movable arm and a height adjustment pin receiver in the other of the base or the movable arm and the distance between the lower sample surface and the upper sample surface is adjustable via the height adjustment pin. 
     
     
       9. The device of  claim 8 , comprising a detector for detecting contact between the height adjustment pin and the height adjustment pin receiver. 
     
     
       10. The device of  claim 9 , wherein the detector detects completion of an electrical circuit formed by the contact between the height adjustment pin and the height adjustment pin receiver. 
     
     
       11. The device of  claim 10 , wherein the contact between the height adjustment pin and the height adjustment pin receiver is made when the upper sample surface is in direct contact with the lower sample surface in the absence of a sample. 
     
     
       12. The device of  claim 8 , wherein the height adjustment pin is connected to an actuator. 
     
     
       13. The device of  claim 12 , wherein the height adjustment pin is a precision screw and the actuator is a motor. 
     
     
       14. A method of measuring cells or particles in a suspension, comprising:
 (a) providing a device comprising:
 (i) a bright-field light source; 
 (ii) at least one optional fluorescence excitation source; 
 (iii) an imaging system; and 
 (iv) a sample mounting system for samples of the suspension of cells or particles, comprising:
 (A) a base having a base top side, a base bottom side, and an objective lens cavity located on the base so as to align with and receive one or more objective lenses of the imaging system; and 
 (B) a hinge fixed to the base; 
 (C) a movable arm fixed to the hinge, said movable arm having a movable arm top side, a movable arm bottom side, and a bright-field light source cavity located on a portion of the movable atm distal to the hinge and configured to receive the bright-field light source; 
 (D) a lower sample surface mounted to the base top side in a position configured to receive bright-field light from the bright-field light source when the movable arm is in a closed position; and 
 (E) an upper sample surface mounted to the movable arm bottom side of the movable arm in a position configured to receive bright-field light from the bright field light source; 
 wherein a distance between the lower sample surface and the upper sample surface when the movable arm is in the closed position is adjustable to accommodate variable volumes of liquid sample deposited between the upper and lower sample surfaces; 
 
 
 (b) loading a sample of known volume of the suspension of cells or particles onto the lower sample surface; 
 (c) before, after, or simultaneously with step (b), moving the movable arm to the closed position relative to the base; 
 (d) illuminating the sample via the bright-field light source, the at least one optional fluorescence excitation source if present, or a combination thereof; 
 (e) detecting and measuring the cells or particles via the imaging system to produce measurement data; 
 (f) before, after or simultaneously with step (b), (c), (d) or (e), adjusting the distance between the lower sample surface and the upper sample surface to accommodate the volume of sample loaded onto the lower sample surface; and 
 (g) preparing the device for repeating steps (b)-(f) by moving the movable arm into an open position relative to the base and removing the sample from the upper and lower sample surfaces. 
 
     
     
       15. The method of  claim 14 , wherein the device further comprises one or more of (a) a plurality of objective lenses of the imaging system, and (b) a plurality of fluorescent excitation sources. 
     
     
       16. The method of  claim 14 , wherein the sample comprises a suspension of cells, selected from prokaryotic and eukaryotic cells. 
     
     
       17. The method of  claim 14 , wherein the sample mounting system comprises a height adjustment pin in one of the base or the movable arm and a height adjustment pin receiver in the other of the base or the movable arm and the distance between the lower sample surface and the upper sample surface is adjusted via the height adjustment pin. 
     
     
       18. The method of  claim 17 , wherein the height adjustment pin is connected to an actuator. 
     
     
       19. The method of  claim 18 , wherein the height adjustment pin is a precision screw and the actuator is a motor. 
     
     
       20. The method of  claim 14 , comprising the further steps of:
 (h) adjusting the volume of sample on the lower sample surface based on the measurement data; and 
 (i) repeating steps (b) through (g). 
 
     
     
       21. The method of  claim 14 , further comprising setting a zero gap measurement by determining a distance between a point on the movable arm and a point on the base when the upper sample surface and the lower sample surface are in direct contact in the absence of a sample. 
     
     
       22. The method of  claim 21 , wherein the device comprises a height adjustment pin in one of the base or the movable arm and a height adjustment pin receiver in the other of the base or the movable arm, and the method comprises setting the zero gap measurement by (1) placing the upper sample surface in direct contact with the lower sample surface in the absence of a sample, (2) moving the height adjustment pin into contact with the height adjustment pin receiver, and (3) detecting the contact between the height adjustment pin and the height adjustment pin receiver when the upper sample surface is in direct contact with the lower sample surface in the absence of a sample. 
     
     
       23. The method of  claim 22 , wherein the contact between the height adjustment pin and the height adjustment pin receiver completes a circuit and the detection comprises detecting the completion of the circuit. 
     
     
       24. The method of  claim 23 , wherein the contact between the height adjustment pin and the height adjustment pin receiver is detected by a distance sensor.